Multiple SCM repositories in Jenkins - Step-by-Step Execution

Process Flow - Multiple SCM repositories

Start Jenkins Job

↓

Load SCM Configurations

↓

Checkout SCM Repo 1

↓

Checkout SCM Repo 2

↓

Run Build Steps

↓

Complete Job

Jenkins loads multiple SCM repository settings, checks out each repository in order, then runs build steps.

Execution Sample

Jenkins

pipeline {
  agent any
  stages {
    stage('Checkout') {
      steps {
        checkout([$class: 'GitSCM', userRemoteConfigs: [[url: 'https://repo1.git']]])
        checkout([$class: 'GitSCM', userRemoteConfigs: [[url: 'https://repo2.git']]])
      }
    }
  }
}

This Jenkins pipeline checks out two separate Git repositories sequentially.

Process Table

Step	Action	SCM Repo URL	Result	Notes
1	Start Jenkins Job	-	Job started	Initial job trigger
2	Load SCM Configurations	https://repo1.git, https://repo2.git	Configurations loaded	Both repo URLs read
3	Checkout SCM Repo 1	https://repo1.git	Repo 1 checked out	Workspace updated with repo1 files
4	Checkout SCM Repo 2	https://repo2.git	Repo 2 checked out	Workspace updated with repo2 files alongside repo1
5	Run Build Steps	-	Build steps executed	Build uses files from both repos
6	Complete Job	-	Job finished successfully	All steps done

💡 Job ends after checking out both repositories and running build steps

Status Tracker

Variable	Start	After Step 3	After Step 4	Final
Workspace contents	empty	files from repo1	files from repo1 + repo2	files from repo1 + repo2

Key Moments - 2 Insights

Why do we see files from both repositories in the workspace after checkout?

Because Jenkins runs two separate checkout steps (see execution_table steps 3 and 4), it adds files from each repo into the workspace without removing the previous ones.

Does the second checkout overwrite the first repository's files?

No, the second checkout adds its files alongside the first repo's files, so both sets coexist in the workspace (execution_table step 4).

Visual Quiz - 3 Questions

Look at the execution table, what happens at step 4?

A Checkout of the first repository

B Checkout of the second repository

C Build steps execution

D Job completion

💡 Hint

Refer to the 'Action' and 'SCM Repo URL' columns in execution_table row 4

According to variable_tracker, what does the workspace contain after step 3?

A Empty workspace

B Files from repo2 only

C Files from repo1 only

D Files from both repo1 and repo2

💡 Hint

Check 'After Step 3' column for 'Workspace contents' in variable_tracker

If the second checkout was removed, how would the workspace contents change after the job?

A Workspace would contain only repo1 files

B Workspace would be empty

C Workspace would contain only repo2 files

D Workspace would contain files from both repos

💡 Hint

Look at variable_tracker and execution_table steps 3 and 4 to understand checkout effects

Concept Snapshot

Jenkins can checkout multiple SCM repositories by running multiple checkout steps.
Each checkout adds files to the workspace without removing previous ones.
Use separate checkout commands for each repo URL.
Build steps can then use files from all checked-out repos.
This allows combining code from different sources in one job.

Full Transcript

This visual execution shows how Jenkins handles multiple SCM repositories in one job. The job starts and loads configuration for two Git repositories. It then checks out the first repository, adding its files to the workspace. Next, it checks out the second repository, adding its files alongside the first. The workspace now contains files from both repositories. Build steps run using these combined files. Finally, the job completes successfully. The variable tracker confirms the workspace contents after each checkout. Key points include that each checkout adds files without overwriting previous ones, allowing multiple repos to coexist in the workspace.